Young Boars Research Articles

Classical, Molecular, and Genomic Cytogenetics of the Pig, a Clinical Perspective.

Simple SummaryChromosome rearrangements are one of the main etiological factors leading to impaired fertility in the domestic pig. The high prevalence of chromosome rearrangements in swine herds, coupled with the production of significantly lower litter sizes, has led to the implementation of cytogenetics techniques in screening prospective breeding boars for rearrangements. Beginning in the 1960s, classical cytogenetics techniques have been applied in laboratories, resulting in the identification of over 200 distinct chromosome rearrangements in the pig. More recently advances in technology, and the development of molecular cytogenetics and cytogenomics techniques, have enhanced the resolution of rearrangements and advanced diagnostic techniques, allowing for more precise and rapid diagnosis of rearrangements.The chromosomes of the domestic pig (Sus scrofa domesticus) are known to be prone to reciprocal chromosome translocations and other balanced chromosome rearrangements with concomitant fertility impairment of carriers. In response to the remarkable prevalence of chromosome rearrangements in swine herds, clinical cytogenetics laboratories have been established in several countries in order to screen young boars for chromosome rearrangements prior to service. At present, clinical cytogenetics laboratories typically apply classical cytogenetics techniques such as giemsa-trypsin (GTG)-banding to produce high-quality karyotypes and reveal large-scale chromosome ectopic exchanges. Further refinements to clinical cytogenetics practices have led to the implementation of molecular cytogenetics techniques such as fluorescent in-situ hybridization (FISH), allowing for rearrangements to be visualized and breakpoints refined using fluorescently labelled painting probes. The next-generation of clinical cytogenetics include the implementation of DNA microarrays, and next-generation sequencing (NGS) technologies such as DNA sequencing to better explore tentative genome architecture changes. The implementation of these cytogenomics techniques allow the genomes of rearrangement carriers to be deciphered at the highest resolution, allowing rearrangements to be detected; breakpoints to be delineated; and, most importantly, potential gene implications of those chromosome rearrangements to be interrogated. Clinical cytogenetics has become an integral tool in the livestock industry, identifying rearrangements and allowing breeders to make informed breeding decisions.

Performance, Carcass and Relative Organ Weights of Young Boars Fed Graded Dietary Levels of Raw Icacinia manni (Earth Ball)

A study conducted for a period of fifty (50) days to determine the growth performance, carcass and organ weight of growing boars fed graded dietary levels of raw Icacinia manni tuber meal. Four experimental diets were formulated with Icacinia manni (Earth ball) replacing maize at 0, 5, 10 and 15% levels designated as T1(control), T2, T3 and T4, respectively. Forty-eight (48) young boars (Landrace x Large white) each weighed 7.72+ 0.35kg were assigned to the four dietary treatments and replicated three times of four boars each in a completely randomized design. Carcass traits and relative organs weights were evaluated. These traits were; dressed weight, dressing percentage, head, shank, trotter, belly, thick rib chop, rib chop, loin, chump chop, leg fillet end, Leg shank end, liver, lungs, kidney spleen and heart. The results indicated that apart from T4, diets T1, T2 and T3 did not differ significantly (P>0.05) in terms of feed intake, weight gain and feed conversion ratio. This implies that Icacinia manni did not affect growth performance except at 15% level of inclusion Similarly, Pigs fed diets T2 and T3 showed significant (P<0.05) increase in dressed weight, dressing percentage as well as certain primal cuts such as breast, rib chop, loin and chump chop. However, relative organs weight did not differ (P>0.05) across dietary treatments except the lungs in T4 (15%) signifying the non-deleterious effect of raw icacinia manni, at 10%. To attain optimum performance and carcass characteristics in young boars therefore, inclusion of raw Icacinia manni in young boars’ diet at 10 percent is recommended.

Evaluation of the reproductive ability of crossbred sows obtained from different breeding boars

In order to improve the livestock industry, and push up it to the world level making full use of the biological features of animals it is necessary to radically improve the system of breeding work with the species selection and the best combinations to obtain the fattening of young animals, in the implementation of this task special emphasis on the pig as the most precocious and technologically advanced livestock industry. The advantage of pork production is evidenced by the economic assessment of meat production of diff erent types of animals according to the level of individual costs for the nutrients of the product. It is no coincidence that the growth rate of pork production in the world in recent years exceeds the growth rate of beef and poultry. The purpose of the work was to assess the reproductive traits of crossbred sows obtained from various dreeding boars of Landrace breed (1st paternal breed) and mated with breeding boar of Duroc breed (2nd paternal breed) during three-breed industrial crossbreeding. The research has been carried out on the basis of LLC “Agrofi rma Ariant” in the Chelyabinsk region. It has been found that among the analyzed crossbreds the highest reproductive abilities were distinguished by sows obtained from the breeding boar No. 62143 their prolifi cacy was 13,5 heads live piglets, and the live weight of 1 piglet at birth was 1448,07 g, which exceeded the indicators of sows daughters of breeding boar No. 620001 by 1,4 piglets, and 17,9 g, respectively. Approximately the same number of female pigs has been obtained in both study groups. The number of young boars from sows of breeding boar No. 62143 was by 1,3 head more. Thus, in order to increase the profi tability of pork production in LLC “Agrofi rma Ariant” it is necessary to increase the volume of use of sperm of breeding boar No. 62143 of Landrace breed

Infestation of wild boar meat from the Eastern Lublin province with Alaria mesocercariae

The study was aimed at assessment of the usefulness of a digestion method, a standard procedure for routine examination of wild boar meat for Trichinella, in detecting the presence of Distomum musculorum suis (DMS) in the population of wild boars from the Eastern Lublin province. The study material included 500 samples collected from the diaphragm pillars of 250 young boars (6-12 months) and 250 boars above one year of age. First, the meat was tested with the digestion method that is a referential procedure for trichinosis detection. Then, the samples in which over ten mesocercariae were found were assessed with an Alaria-Migration Technique (AMT). The digestion method confirmed the presence of Alaria mesocercariae in 42 carcasses of young boars (16.8 %) and 117 samples of animals older than one year (46.8 %). The study showed a diversified intensity of the parasite presence in the carcasses of individual animals. The invasion intensity ranged from 1 to 18 parasites in 50 g of meat in the young animals, and from 1 to 22 larvae in the older individuals. The carcasses of eight young and thirty two older animals contained over 10 parasites per 50 g of the meat, which accounted for 3.2 % and 12.8 % animals per respective age group. AMT analysis also indicated variable intensity of the parasite infestation, amounting to 32-57 mesocercariae in young animals and 31-71 larvae in the older ones. The study demonstrated an almost three times higher efficiency of the AMT method than the digestion method, which made us conclude that the former should be recommended for Alaria detection. The digestion method used for routine detection of Trichinella, despite its lower accuracy in diagnosing Alaria mesocercariae, can be also employed for the detection of DMS in the case of intensive parasite infection. Our study confirmed high prevalence of the parasite among wild boars from the Eastern Lublin Province. We also found that the invasion intensity depended on the animal age and was higher in older individuals. Considering the zoonotic nature of alariosis and its frequency, it poses an increasingly common problem for official veterinarians during the sanitary and veterinary evaluation of wild boar meat.

Genetic parameter estimation and gene association analyses for meat quality traits in open-air free-range Iberian pigs.

Meat quality of Iberian pigs is defined by the combination of their genetic characteristics and the particular production system. To carry out a genetic analysis of the main meat quality traits, we estimated their heritabilities, genetic correlations and the association effects of 32 selected SNPs of 12 candidate genes. A total of ten traits were measured in longissimus dorsi samples from 1,199 Iberian pigs fattened in the traditional free-range system: water holding capacity (thawing, cooking and centrifuge force water losses), instrumental colour (lightness L*, redness a* and yellowness b*), myoglobin content, shear force on cooked meat, and shear force and maximum compression force on dry-cured loin. Estimated heritability values were low to moderate (0.01 to 0.43) being the lowest for L* and the highest for cooking loss. Strong genetic correlations between water holding capacity traits (0.93 to 0.96) and between myoglobin content and a* (0.94) were observed. The association analyses revealed 19 SNPs significantly associated with different traits. Consistent and strong effects were observed between PRKAG3 SNPs (rs319678464G>C and rs330427832C>T), MYH3_rs81437544T>C, CASP3_rs319658214G>T and CTSL_rs332171512A>G and water losses. Also for CAPN1_rs81358667G>A and CASP3_rs319658214G>T and shear force. The SNPs mapping on PRKAG3 showed the highest effects on Minolta colour traits. Genotyping of these SNPs could be useful for the selection of Iberian young boars with similar estimated breeding values for productive traits.

Breeding and Economic Aspects of Cytogenetic Screening Studies of Pigs Qualified for Reproduction.

Simple SummaryThe cytogenetic screening of pigs, carried out using continually refined cytomolecular techniques, enables a precise diagnosis of chromosomal abnormalities that cause developmental anomalies and considerably reduce the fertility (by several dozen to 100%) and performance parameters of breeding herds, resulting in substantial financial losses. Due to the potential spontaneous occurrence of chromosomal aberrations and the rapid spread of these genetic defects in the population, especially under artificial insemination conditions, it is necessary to perform cytogenetic monitoring of animals qualified for reproduction, which is an important criterion when formulating specific selection guidelines.Cytogenetic monitoring allows the identification and early removal of pigs affected by inherited karyotype defects from breeding herds. These abnormalities cause developmental anomalies, considerably reducing the fertility (by several dozen to 100%) and performance parameters of breeding herds, resulting in substantial financial losses. This mainly concerns reciprocal translocations, typical of pigs, which are highly prevalent (about 0.46%), generally occur de novo, and normally result in low breeding soundness of the carriers. Due to the potential spontaneous occurrence of chromosomal aberrations and the rapid spread of these genetic defects in the population, especially under artificial insemination conditions, it is necessary to perform routine karyotype screening of animals qualified for reproduction. The cytogenetic screening program for young boars, carried out using continually refined diagnostic techniques, permits a precise and reliable karyotype assessment, identification of chromosomal abnormalities, and formulation of specific selection guidelines.

PHENOTYPIC CONSOLIDATION COEFFICIENTS OF BIRTH-WEIGHT INDICATORS IN SOWS OF WELSH BREED

The aim of the research was to study the effect of sow and boar age on average weight of newly born piglets, considering the season of the year and the age of the animals. The studies were conducted in the research farm of SE “Gontarivka”, Volchansky district, Kharkiv region. Natural breeding of sows is used for reproduction on the farm. The insemination of sows was carried out according to the scheme of studies. 35 head of sows and 4 boars of different ages and live weights were selected. Four groups of sows were formed. In order to study the impact of the season of the year on sow productivity, the first series of studies were conducted in the autumn, the second series - in the spring according to the same scheme. In different groups of animals, average weight of newly born piglets ranged from 1.10 to 1.21 kg. The average value of this indicator for all sows for both studied seasons was 1.16 kg. The magnitude (for all sows of the period) in winter farrowing was 1.74 % higher than the summer farrowing (for all sows of the period), although the difference between these groups was not probable. Between the sows of different ages, inseminated by boars of different ages, in winter, the higher values were given to young sows that were inseminated by young boars (p<0.01 compared to young sows that were inseminated by full-grown boars). Among the sows of different ages, inseminated by boars of different ages, in the summer, the highest values were middle-aged, which were inseminated by middle-aged boars (p<0.01 compared to young sows in winter, inseminated by full boars and p<0.05 compared to young sows in summer, which were inseminated by adult boars). During the summer period the middle-aged sows, which were inseminated by middle-aged boars, received maximum values of average weight of newly born piglets, which were higher than sows of other groups by 10.00-0.83 %. The most consolidated high-birth-weight rates were obtained in winter for young sows that were inseminated by adult boars. In the summer, the most consolidated were young sows inseminated by young boars.

The effect of varicocele on semen quality in boars exposed to heat stress.

Semen quality has a dramatic impact on reproductive efficiency in the swine industry, influencing both conception rate and litter size. The objective of this study was to assess whether the presence of varicocele hinders semen quality in both thermoneutral and heat stress (HS) conditions. At approximately 6 mo of age, ultrasonography was used to measure left and right pampiniform plexus area in order to detect varicocele in maternal line boars at the University of Nebraska–Lincoln. Between 10 and 12 mo of age, semen was collected from each boar (n = 28) twice weekly. Boars were collected under thermoneutral conditions, were then heat stressed for 7 d to exacerbate any semen quality issues, and semen was collected post-HS for 6 wk. Sperm characteristics were determined by computer-assisted semen analysis. The presence of varicocele had a significant effect on sperm concentration (P = 0.04) and trended toward significance for mean sperm head area (P = 0.06) throughout the duration of the study. An interaction existed between varicocele and collection time point at weeks 2–5 post-HS for distal droplet percentage, suggesting that boars with varicocele were possibly more susceptible to heat-stress-induced semen quality issues than boars without varicocele. Moreover, semen quality was reduced in boars with versus without varicocele under both thermoneutral and HS conditions. Therefore, detection of varicocele by ultrasound could represent a potential marker of fertility in young boars or as a component trait in selection indices for fertility.

Удосконалення алгоритму критеріїв добору свиней батьківської форми за використання методу BLUP

The purpose. To improve algorithm of criteria of selection of pigs of male parental form by results of assessment of animals of 4 generations with the help of BLUP method. Methods. Theoretical and methodological basis of research were works by Ch.R. Henderson, R.A. Mrode, V.M. Kuznetsov, N.P. Yudina, and other scientists on the investigated problem. During researches they applied general trial-and-error method: measurement, comparison, simulation; and special — BLUP, zoo-technical, instrumental, etc. Biometrical analysis of data was carried out with the help of statistical and mathematical methods, realized in package Statistica 6. Results. Researches testify to the following: selection of pigs in herd with the use of BLUP-index assessment is necessary for realizing in some stages, proceeding from the reached level of productivity, and also the purposes and problems of selection. For preliminary determination of the best alternatives of selection of young boars and pigs they simulated 5 levels of selection pression on terminal BLUP-index. With increase of selection pression they traced dynamics of values of attributes of specific breeding value of animals which treated to different pleiads, for the purpose of stabilization of their reproductive qualities. At the final stage the selection of young boars and pigs was spent on minimum acceptable values: terminal BLUP-index, specific breeding value of daily average increase, width of fat, length of a trunk and amount of papillae. Simulation of results of selection at the improved algorithm of criteria of selection in herd testifies to the following: selection effect for one generation on specific breeding value of width of fat and daily average increase makes–0,53 mm and +4,66 g accordingly. Conclusions. By results of researches it is established that development of algorithm of selection of animals of male parental form promoted increase of genotypic consolidation of young boars on specific breeding value of daily average increase and width of fat on 50,8 and 65,6%, and young pigs — on 23,1 and 32,6% accordingly.

SARKOCYSTOSIS OF BOARS AND WILD DUCKS IN THE NORTH OF THE NON-BLACK EARTH AREA

Sarcocystosis (sarkosporidiosis) is a widespread, but insufficiently studied, protozoal disease of farm animals and humans, wild animals and birds. Sarcocystosis was not registered in wild animals in the territory of the Kirov region.Samples from 218 carcasses of wild boars caught in various parts of the Kirov region from 2011 to 2019 were examined for spontaneous defeat by sarcocystosis. Samples were taken from various muscle groups and the heart. They were examined by visual inspection methods and using a compressor. In the selection of muscle samples, we took into account the area, age, sex, fatness of the animal.In a study of 191 boar carcasses in 2012–2017, we did not identify sarcocysts in the muscles and heart. Sarcocistosis in wild boars in the north of the Non-Black Earth Region was registered in the last hunting season of 2018–2019 in the study of 27 carcas boars. The extensiveness of invasion was 25,9%, the intensity of invasion is low – 4,3±1,3 (1–14) cysts in the compressor. The length of the sarcocysts is 0,5–1,36 (0,88±0,1) mm, the width is 0,12–0,18 (0,15±0,01) mm. The infection rate of young boars was 57,1%.Sarcocystosis in wild duck mallards was registered by us in May 2011. Cysts were 4x1 mm, white colored. The intensity of invasion in wild ducks was high. We found Sarcocystis rileyi in wild ducks from the Nizhny Novgorod and Vologda regions.

Logistic regression analysis of the related factors in discarded semen of boars in Southern China

This study aimed to investigate factors affecting the discarded semen of boars. A total of 176,368 ejaculates of boars from nine AI centers were collected from January 2013 to May 2016 in Southern China. The criteria for determining whether their semen was abnormal included cytoplasmic droplets, coiling tail, sperm agglutination, impurity, poor motility, oligozoospermia, necrozoospermia, azoospermia, and hemospermia. The cause of discarded semen was evaluated with a Chi-square test, and the effects of housing type, breed, age at collection, season identified in the northern hemisphere, and age at herd entry of the discarded semen of boars were analyzed with a logistic regression model. Results indicated the proportion of the discarded semen (PDS) in the nine AI centers was 13.09%. Chi-square test showed the greatest PDS among all causes was found in semen discarded due to cytoplasmic droplets (31.60%), followed by impurity (25.96%), sperm agglutination (20.31%), coiling tail (17.72%), oligozoospermia (10.86%), and others (6.78%; P < 0.0001). Logistic regression analysis revealed the PDS was affected by all these five factors (P < 0.0001). The PDS of boars raised individually in stalls was greater than that of boars raised individually in pens (OR: 1.657; 95% CI: 1.607 to 1.709). The PDSs of Duroc boars (OR: 1.130; 95% CI: 1.093 to 1.167) and Yorkshire boars (OR: 1.432; 95% CI: 1.380 to 1.486) were greater than that of Landrace boars. The PDSs of adult boars (aged from 13 to 24 mo, from 25 to 36 mo, and more than 37 mo with OR: 0.800, 0.941, and 0.838, respectively; 95% CI: 0.771 to 0.831, 0.902 to 0.983, and 0.790 to 0.889, respectively) were lower than those of young boars (aged less than 12 mo). The PDSs of semen collected in summer (OR: 1.367; 95% CI: 1.314 to 1.422), autumn (OR: 1.185; 95% CI: 1.138 to 1.234), and winter (OR: 1.159; 95% CI: 1.115 to 1.206) were greater than those of semen obtained in spring. The PDSs of boars introduced at ages of 5–7 mo (OR: 1.432; 95% CI: 1.380 to 1.486) and 10–12 mo (OR: 1.432; 95% CI: 1.380 to 1.486) were greater than those of boars introduced at an age of 8 and 9 mo. In conclusion, logistic regression analysis reveals discarded semen is affected by housing type, breed, age at collection, season, and age at herd entry. More importantly, cytoplasmic droplets is the primary reason for discarding boar semen, and 8 months at herd entry is the most suitable age for boar introduction.

The effect of porcine circovirus type 2 (PCV2) vaccination of male piglets on sperm quality at the age of puberty

The objective of the study was to investigate the effect of porcine circovirus type 2 (PCV2) vaccination in piglets on sperm quality of young boars. A total of 136 sows were divided in four groups of 34 animals each (17 vaccinated with Circovac®, Merial and 17 unvaccinated in each group). A total of 1 200 piglets were selected, half of which were vaccinated against PCV2 on the 21st day (Porcilis® PCV, MSD) and the other half was left unvaccinated. Four groups of 300 pigs each were formed as follows: PS group (vaccinated sows + piglets), S group (vaccinated sows + unvaccinated piglets), P group (unvaccinated sows + vaccinated piglets), C group (unvaccinated sows + piglets). Furthermore, 80 boars (20 piglets per group) were selected and slaughtered at the age of 5.5 months and weight of 95 ± 5.5 kg and their epididymal sperm was collected and evaluated for motility and kinetics, concentration and morphology. Additionally, 10 pigs from each group were used for blood sampling and serological testing for PCV2 IgM and IgG antibodies at the age of 21, 70, 110 and 150 days. The IgG and IgM patterns suggested that the piglets were coming into contact with PCV2 early in life. The S group demonstrated significantly lower curvilinear velocity (VCL, μm/s), amplitude of lateral head displacement (ALH, μm) and significantly higher head abnormalities (%) compared to other groups (P&lt; 0.05). In conclusion, vaccinated young boars showed some improved epididymal sperm kinetic indices and head morphology.

The effect of carcass weight on chemical characteristics and fatty acid composition of Longissimus dorsi and Semimembranosus muscles of European wild boar (Sus scrofa scrofa) meat

The objective of this study was to investigate the effect of carcass weight on chemical characteristics and fatty acid composition of m. longissimus dorsi and m. semimembranosus of European wild boar (Sus scrofa scrofa) meat. The research was carried out on 50 wild boars shot during four battues at hunting reserves in the central part of Poland. The carcasses were divided into three groups: ≤30 kg (G1), 31–45 kg (G2), and &gt;45 kg (G3). The protein concentration increased with carcass weight (P ≤ 0.01). The concentration of saturated fatty acids was influenced by carcass weight and was higher when weight increased. A significantly higher level of monounsaturated fatty acids (MUFA) was found in the carcasses of wild boars from G3 compared with G1 group (P ≤ 0.01). The content of C18:2n-6 was significantly lower in the lightest carcasses compared with the heaviest (P ≤ 0.05). Statistical analysis confirmed that carcasses weight significantly affected polyunsaturated fatty acids (PUFA) n-3 content. The lightest carcasses contained a significantly higher concentration of PUFA n-3 (P ≤ 0.01). In addition, in G3, the amount of C22:5n-3 was two-fold lower (P ≤ 0.01) than in G1. The research has shown that the meat quality was affected by the carcass weight, resulting better parameters in the lighter than in the heavier carcasses. Therefore, most of the culled wild boars should be squeakers and young boars after the first year of life.

Suitability of Japanese wild boar tooth enamel for use as an Electron Spin Resonance dosimeter

The objective of this study was to determine the suitability of Japanese wild boar tooth enamel to evaluate lifetime radiation doses using Electron Spin Resonance Dosimetry (ESR). The opportunity to utilize tooth enamel of Japanese wild boar as a dosimeter is of particular interest due to their importance in the ecosystem within the Fukushima Exclusion Zone. Relevant characteristics were investigated which included the degree of linearity and variability in dose response of wild boar tooth enamel in the range of 1.2–12 Gy. The tooth enamel was found to have a linear dose response in this range. Teeth harvested from the same boar exhibited a variation in dose response ranging from 3.4 to 79.9%. Tooth enamel from deciduous teeth of young boar exhibited greater uniformity in radiation dose response than permanent tooth enamel taken from old boar. This finding suggests that the additive dose method would be more appropriate for performing precise dose reconstructions using tooth enamel of old boar. Preliminary results for retrospective doses varied between 0.2 and 1.4 Gy. Critical level and decision level doses were calculated for the samples used in this study, and values suggest that this methodology would be best utilized for wild boar with estimated absorbed doses exceeding 1 Gy. Information obtained during this study will be used with data collected in future studies to determine the suitability of wild boar tooth enamel for use with ESR dosimetry.

Effect of porcine somatotropin on metabolism, testicular size and sperm characteristics in young boars

ABSTRACT The aim of this study was to evaluate the effect of pST injections on metabolism, testicular size, and sperm characteristics in young boars. Sixty 22-day old piglets were divided into two groups: pST (n=30) and Control (n=30). The pST group was submitted to pST injections (90µg/kg body weight) every three days up to 330 days of age. Blood collections were performed weekly. Testicular weight was measures at 22, 82, 142, 202 and 365 days of age. Libido and fresh semen characteristics were evaluated between 150 and 210 days of age. Semen characteristics were also evaluated during a 72h storage period (15ºC). Testosterone, albumin, and phosphorus blood concentrations were higher in the pST group (P&lt;0.05). The pST group had a higher IGF-I concentration in seminal plasma (P=0.05) and higher testicular weight (P&lt;0.001) compared to the Control group. The pST group had higher ejaculate volume (P&lt;0.001), total sperm count (P=0.047) and number of inseminating doses/ejaculate (P=0.047). During the 72h storage period, the pST group had a lower number of morphological alterations (P&lt;0.001) compared to the Control group. In sum, pST injection in young boars increased testosterone concentration, testicular size, and sperm quality.

147 Dietary Zinc and its Effect on Collection Time and Training Quality of Young Boars for Obtaining Ejaculates

It is known that Zinc (Zn) is important in several aspects of reproduction, including fertility and the production of sexual hormones. The aim of the present study was to evaluate different amounts and types of Zn on ejaculate collection time and training behaviour of young boars. For this purpose, non-castrated domestic boars (York × Landrace, Sus scrofa domesticus), with an average age of 6.8 months and initial weight of 120 kg (body condition score of 3), were assigned to 3 different groups (5 per group). The base diet consisted of cereal-soybean feed, complemented with a mixture of minerals and vitamins without the addition of extra Zn. The Zn concentration was determined using atomic absorption photospectrometry, specifically, with a Varian SpectrAA 220 Atomic Absorption Spectrometer (Varian, Palo Alto, CA, USA) and following manufacturer instructions. The effect of Zn was evaluated by administering the young boars different amounts and sources of the mineral: (1) Control = 25 ppm of Zn, (2) T1 = Control + 125 ppm ZnSO4 (inorganic), and (3) T2 = Control + 125 ppm Zn-methionate (Zn-Met, organic). The boars were given an adaptation period of 15 days to acclimate to the feed, and afterwards they underwent the training process for ejaculate collection for 4 more weeks. Boars were collected an average of 2.95, 2.67, and 2.69 times for Control, T1, and T2. Several variables were used in order to determine the existence of treatment effects, including number of training sessions (NTS); interval between training (days, IBT); false mounts (mounting dummy but dismounting before allowing semen collection, FM); effective mounts (duration of mounting dummy and completion of semen collection, EM); and duration of ejaculation (min, DE). The results were analysed with PROC MIXED using the statistical package SAS (SAS Institute Inc., Cary, NC, USA), with statistical differences set at α &lt; 0.05. Even though significant differences were not observed between most of the variables analysed (e.g. NTS, FM, EM, DE), differences did exist between treatments for the variable IBT (P = 0.013). Notably, although there was no significant difference between treatments for the variable DE, it was higher for T3 (6.49 min, P = 0.54) than for T1 and T2 (5.87 and 5.27 min, respectively). In conclusion, the addition of 150 ppm of organic Zn (i.e. Zn-Met) significantly reduced the time interval for training the boars, which may be due to a better libido, and demonstrated the importance of considering types and dose amounts of dietary Zn and its effects on reproduction.

The effect of age, interval collection and season on selected semen parameters and prediction of AI boars productivity

The possibility of planning the production level has a special importance for AI stations, and its inaccuracy should be minimized by eliminating the factors differentiating the quantity and quality of the ejaculate. The aim of the study was to determine the effect of age, collection interval and season on selected quantitative and qualitative semen parameters and to develop equations for estimating production capacity for AI stations. The study included 48 117 ejaculates. Experimental groups were created according to: age of boar (8–9, 10–12, 13–18, 19–24, 25–30, >30 months), collection interval (≤2, 3, 4, 5, 6, 7, ≥8 days), and season (Winter, Spring, Summer, Autumn). Selected quantitative and qualitative parameters were analyzed: semen volume (ml), spermatozoa concentration (×106ml−1), total number of spermatozoa in ejaculate (×109), number of motile spermatozoa in ejaculate (×109), and number of insemination doses obtained from one ejaculate (n). The most important role in shaping the results was played by interactions. The highest semen volumes were achieved for the oldest boars after 7-day interval collection during Autumn (about 300ml). Interestingly, the lowest semen volumes were also noted during Autumn from the youngest boars after 1–2 and 7-day interval collection (a little over 160ml). The highest spermatozoa concentrations (515×106ml−1) were observed in Autumn for 10–12 month-old boars with the longest interval collection, which clearly demonstrates the positive impact of long resting on young boars. The lowest spermatozoa concentrations – below 300×106ml−1 – were reported for the oldest boars after 1–2 and 3-day collection intervals. The highest total number of spermatozoa in ejaculate and motile spermatozoa were noted during the longest collection interval in Winter at the ages of 13–18 months and 25–30 months, while the lowest occurred in the same season with a short interval from the 10–12 month boars. Almost all correlations were statistically proven at the level of P≤0.05 and P≤0.01, except for the correlation between the number of motile spermatozoa and the age of boars. Developed regression equations enable, with a high degree of accuracy, the estimation of the selected ejaculate parameters on the basis of age, collection interval and season. The solution proposed in the article is a useful tool, especially for AI stations or large farms with a high rate of boars producing semen for AI. AI stations assessing the long-term production capacity of boars should take into account the factors examined in this study. Underestimation of the interaction may, in fact, reduce the number of insemination doses by up to 5 portions of a single ejaculate.

Wyniki oceny przySyciowej knurk�w czysto rasowych wyprodukowanych w Polsce w bydgoskim okregu hodowlanym w latach 2011-2014

The research covered the results of 7555 young boars of following breeds: Polish Large White (PLW), Polish Landrace (PL), Hampshire, Duroc and Pietrain performance tested in years 2011-2014 in Poland in The Bydgoszcz Breeding Region. Among pure breed young boars performance tested in The Bydgoszcz Breeding Region in years 2011-2014 young boars of Hampshire breed had the highest daily gain of body weight standardised on 180th day of life. From 2011 till 2014 an improvement occurred thus decrease of backfat thickness in P2 and P4 points in all examined groups of young boars (except Pietrain pigs). The highest height of loin eye had animals of Hampshire breed (2011, 2012, 2013, 2014) and Pietrain breed (2011, 2013 and 2014). Pietrain pigs had the highest meat content. The highest selection index value showing the highest breeding value in range of growth and slaughter traits had Hampshire and Pietrain young boars. Analyzing the results from years 2011 and 2014 it was observed that a significant increase of performance test selection index value occurred in all examined pure breed young boars (except Pietrain), thus Polish Large White, Polish Landrace, Hampshire and Duroc by 16, 10, 9 and 12 points, respectively. In range of analyzed traits significant differences were generally observed among examined groups of animals in particular years and in a total years summary. Also significant differences were proved regarding to tested traits of pure breed young boars among examined years.

The dependence of the growth rate and meat content of young boars on semen parameters and conception rate

Boars have a decisive impact on the progress in pig production, however, there is no recent information about the optimal growth parameters during the rearing period for modern breed later used in artificial insemination (AI) stations. Therefore, the objective of the research was to conduct semen parameter and conception rate analyses on the basis of growth rate and meat content assessments made during the rearing of AI boars of different genotypes. The study was carried out between 2010 and 2014 and included 184 boars in five breed combinations: 46 Polish Large White, 50 Polish Landrace, 27 Pietrain, 36 Duroc×Pietrain and 25 Hampshire×Pietrain. Boars were qualified by daily gains and meat content assessment (between 170 and 210 days of life). A total number of 38 272 ejaculates were examined (semen volume (ml), spermatozoa concentration (×106 ml−1), total number of spermatozoa (×109) and number of insemination doses from one ejaculate (n)). The fertility was determined by the conception rate (%). Semen volume, spermatozoa concentration and conception rate (P<0.01), followed by the total number of spermatozoa and insemination doses (P<0.05) were characterized by the highest variability in relation to breed of boars. The effect of daily gains was reported for spermatozoa concentration, number of insemination doses, conception rate (all P<0.01) and total number of spermatozoa (P<0.05). The peak of growth for spermatozoa concentration, total number of spermatozoa, insemination doses and conception rate was achieved for 800 to 850 g gains. Meat content affected semen volume, number of insemination doses and conception rate (P<0.05). Rearing boars while maintaining daily gains at the 800 to 850 g level and 62.5% to 65% meat content helps AI stations to increase the efficiency and economic profitability, and the number of insemination doses to increase by up to 300 doses/boar within a year. The analyses of growth parameters may help increase the efficiency and economic viability of AI stations.

Azoospermia and Testicular Hypoplasia in a Boar Carrier of a Novel Y-Autosome Translocation

Few sex-autosome chromosome abnormalities have been documented in domestic animal species. In humans, Y-autosome chromosome abnormalities may occur at a rate of 1/2,000 live births, whereas in the domestic pig only 2 Y-autosome reciprocal translocations have been previously described. During a routine cytogenetic screening of young boars, we identified a new Y-autosome translocation carrier, which after puberty showed semen devoid of sperm and testicular hypoplasia with spermatogenesis arrest. Whole chromosome painting by FISH analysis corroborated the reciprocal nature of the chromosomal exchanges between the Y chromosome and SSC13. The possible causes for the observed meiotic arrest of the carrier are reviewed.